| preliminary studies on an unusual poxvirus of the western grey squirrel (sciurus griseus griseus) of north america. | particles of a poxvirus found in californian western grey squirrels have overall dimensions indistinguishable from those of the poxviruses of the genera orthopoxvirus and leporipoxvirus, but have surface structures somewhat reminiscent of virions of members of the genus parapoxvirus. extracts of tissues infected with the squirrel poxvirus cross-react in gel-diffusion tests with extracts of tissues infected with californian myxoma virus, but not with a similar preparation infected with a south am ... | 1975 | 181346 |
| experimental infection with western equine encephalomyelitis virus in wild rodents indigenous to kern county, california. | six species of rodents from kern county, california, were inoculated subcutaneously with western equine encephalomyelitis (wee) virus to determine their susceptibility to infection and their potential as natural hosts. ammospermophilus nelsoni, citellus beecheyi, dipodomys heermanni, dipodomys nitratoides, peromyscus maniculatus, and sciurus griseus were readily infected. infection was usually fatal in dipodomys species, c. beecheyi, and s. griseus, but was clinically inapparent in other species ... | 1974 | 4426699 |
| survey for evidence of colorado tick fever virus outside of the known endemic area in california. | a virus very similar or identical to colorado tick fever (ctf) virus was recovered from the blood clot of one of 104 black-tailed jack rabbits (lepus californicus) examined during a survey for various zoonotic agents in mammals and ticks from the university of california, hopland field station, mendocino county, california, 1974--79. this is the first reported isolation of a ctf-like virus from l. californicus, and only the second time such a virus has been found in northwestern california. mend ... | 1982 | 7102919 |
| the roles of birds, lizards, and rodents as hosts for the western black-legged tick ixodes pacificus. | we compared the infestation by ixodid ticks of lizards, rodents, and birds collected simultaneously within areas representing common habitat types in mendocino county, ca. lizards were infested only by ixodes pacificus cooley and kohls, birds by i. pacificus and haemaphysalis leporispalustris (packard), and rodents by i. pacificus, i. spinipalpis hadwen and nuttall, i. woodi bishopp, dermacentor occidentalis marx, and d. variabilis (say). infestation by i. pacificus larvae and nymphs of lizards ... | 2004 | 15709249 |
| western gray squirrel (rodentia: sciuridae): a primary reservoir host of borrelia burgdorferi in californian oak woodlands? | in california, dense woodlands have been recognized as important biotopes where humans are exposed to the nymphal stage of the western blacklegged tick, ixodes pacificus cooley & kohls, the primary vector of the lyme disease spirochete borrelia burgdorferi sensu stricto (s.s.), in the far-western united states. to identify the principal reservoir host(s) of this spirochete, and of closely related spirochetes in the b. burgdorferi sensu lato (s.l.) complex, in dense woodlands in mendocino county, ... | 2005 | 15962792 |
| sylvatic maintenance of borrelia burgdorferi (spirochaetales) in northern california: untangling the web of transmission. | lyme borreliosis is associated with several genospecies of borrelia burgdorferi sensu lato (s.l.) (spirochaetales), but human disease has been associated only with borrelia burgdorferi sensu stricto (s.s.) johnson, schmid, hyde, steigerwalt & brenner in the western united states. restriction fragment length polymorphism (rflp) analysis of rrf-rrl amplicons from 124 tick and mammalian isolates from various habitats yielded 13 rflp patterns. of these patterns, six were patterns previously associat ... | 2006 | 16892634 |
| west nile virus infection in tree squirrels (rodentia: sciuridae) in california, 2004-2005. | west nile virus (wnv) transmission generally involves a mosquito vector and an avian reservoir host, with mammals as incidental hosts. although most mammalian wnv infections cause low or no morbidity or mortality, tree squirrels are susceptible to wnv-associated neurologic disease with infection prevalence comparable to that in dead birds. positive species included fox squirrel (sciurus niger), western gray squirrel (s. griseus), and eastern gray squirrel (s. carolinensis). kidney tissue (dissec ... | 2007 | 17488896 |
| differential exposure to anaplasma phagocytophilum in rodent species in northern california. | anaplasma phagocytophilum is a zoonotic tick-borne rickettsial pathogen that causes granulocytic anaplasmosis (ga) in humans, horses, and dogs. in california, dusky-footed woodrats (neotoma fuscipes) are a putative reservoir host, and ixodes pacificus is a vector for transmission from rodents to humans, dogs, and horses. cases are clustered in coastal and sierra nevada foothill regions, but not necessarily in proximity to infected woodrats. this study was designed to compare exposures and active ... | 2008 | 18047398 |
| evaluation of squirrels (rodentia: sciuridae) as ecologically significant hosts for anaplasma phagocytophilum in california. | granulocytic anaplasmosis (ga), caused by anaplasma phagocytophilum, is a potentially fatal, emerging rickettsial disease of humans, domestic animals, and wildlife. the purpose of this study was to determine whether sciurids from multiple areas of northern california were infested with ticks or exposed to or infected with a. phagocytophilum using polymerase chain reaction (pcr) and indirect-fluorescent antibody (ifa) serology. sciurids of nine different tree- and ground-dwelling species were ass ... | 2008 | 18714881 |
| identifying the reservoir hosts of the lyme disease spirochete borrelia burgdorferi in california: the role of the western gray squirrel (sciurus griseus). | we investigated the role of the western gray squirrel (sciurus griseus) as a reservoir host of the lyme disease spirochete borrelia burgdorferi. a survey of 222 western gray squirrels in california showed an overall prevalence of b. burgdorferi infection of 30%, although at a county level, prevalence of infection ranged from 0% to 50% by polymerase chain reaction. laboratory trials with wild-caught western gray squirrels indicated that squirrels were competent reservoir hosts of the lyme disease ... | 2008 | 18840740 |
| population structure of the lyme borreliosis spirochete borrelia burgdorferi in the western black-legged tick (ixodes pacificus) in northern california. | factors potentially contributing to the lower incidence of lyme borreliosis (lb) in the far-western than in the northeastern united states include tick host-seeking behavior resulting in fewer human tick encounters, lower densities of borrelia burgdorferi-infected vector ticks in peridomestic environments, and genetic variation among b. burgdorferi spirochetes to which humans are exposed. we determined the population structure of b. burgdorferi in over 200 infected nymphs of the primary bridging ... | 2009 | 19783741 |
| distribution of the lyme disease spirochete borrelia burgdorferi in naturally and experimentally infected western gray squirrels (sciurus griseus). | the dynamics of borrelia burgdorferi infections within its natural hosts are poorly understood. we necropsied four wild-caught western gray squirrels (sciurus griseus) that were acquired during a previous study that evaluated the reservoir competence of this rodent for the lyme disease spirochete. one animal was infected experimentally, whereas the others were infected in the wild before capture. to investigate dissemination of b. burgdorferi and concurrent histopathologic lesions in different t ... | 2010 | 20017717 |
| coinfection of western gray squirrel (sciurus griseus) and other sciurid rodents with borrelia burgdorferi sensu stricto and anaplasma phagocytophilum in california. | overlapping geographic distributions of tick-borne disease agents utilizing the same tick vectors are common, and coinfection of humans, domestic animals, wildlife, and ticks with both borrelia burgdorferi and anaplasma phagocytophilum has been frequently reported. this study was undertaken in order to evaluate the prevalence of both b. burgdorferi sensu stricto (hereinafter referred to as b. burgdorferi) and a. phagocytophilum in several species of sciurid rodents from northern california, usa. ... | 2010 | 20090047 |
| community ecology and disease risk: lizards, squirrels, and the lyme disease spirochete in california, usa. | vector-borne zoonotic diseases are often maintained in complex transmission cycles involving multiple vertebrate hosts and their arthropod vectors. in the state of california, u.s.a., the spirochete borrelia burgdorferi, which causes lyme disease, is transmitted between vertebrate hosts by the western black-legged tick, ixodes pacificus. several mammalian species serve as reservoir hosts of the spirochete, but levels of tick infestation, reservoir competence, and borrelia-infection prevalence va ... | 2010 | 20380218 |
| transmission cycles of borrelia burgdorferi and b. bissettii in relation to habitat type in northwestern california. | this study was undertaken to determine which rodent species serve as primary reservoirs for the lyme disease spirochete borrelia burgdorferi in commonly occurring woodland types in inland areas of northwestern california, and to examine whether chaparral or grassland serve as source habitats for dispersal of b. burgdorferi- or b. bissettii-infected rodents into adjacent woodlands. the western gray squirrel (sciurus griseus) was commonly infected with b. burgdorferi in oak woodlands, whereas exam ... | 2009 | 20514140 |
| francisella tularensis infection without lesions in gray tree squirrels (sciurus griseus): a diagnostic challenge. | fifteen cases of francisella tularensis infection (tularemia) were identified in western gray (sciurus griseus) and eastern gray (sciurus carolinensis) squirrels submitted to the washington animal disease diagnostic laboratory between 2008 and 2011. all of the squirrels originated in washington state, a geographical area with endemic tularemia in wildlife. nine of the 15 squirrels with f. tularensis infection had gross (2/15) or microscopic (9/15) multifocal necrotizing lesions in the spleen, li ... | 2014 | 24557750 |
| data from camera surveys identifying co-occurrence and occupancy linkages between fishers (pekania pennanti), rodent prey, mesocarnivores, and larger predators in mixed-conifer forests. | these data provide additional information relevant to the frequency of fisher detections by camera traps, and single-season occupancy and local persistence of fishers in small patches of forest habitats detailed elsewhere, "landscape fuel reduction, forest fire, and biophysical linkages to local habitat use and local persistence of fishers (pekania pennanti) in sierra nevada mixed-conifer forests" [10]. the data provides insight on camera trap detections of 3 fisher predators (bobcat [lynx rufus ... | 2016 | 26937448 |
| a synthetic review of notoedres species mites and mange. | notoedric mange, caused by obligately parasitic sarcoptiform notoedres mites, is associated with potentially fatal dermatitis with secondary systemic disease in small mammals, felids and procyonids among others, as well as an occasional zoonosis. we describe clinical spectra in non-chiropteran hosts, review risk factors and summarize ecological and epidemiological studies. the genus is disproportionately represented on rodents. disease in felids and procyonids ranges from very mild to death. kno ... | 2016 | 27608857 |
| parallelisms and contrasts in the diverse ecologies of the anaplasma phagocytophilum and borrelia burgdorferi complexes of bacteria in the far western united states. | anaplasma phagocytophilum and borrelia burgdorferi are two tick-borne bacteria that cause disease in people and animals. for each of these bacteria, there is a complex of closely related genospecies and/or strains that are genetically distinct and have been shown through both observational and experimental studies to have different host tropisms. in this review we compare the known ecologies of these two bacterial complexes in the far western usa and find remarkable similarities, which will help ... | 2016 | 29056734 |
| distribution and diversity of borrelia burgdorferi sensu lato group bacteria in sciurids of california. | california has a remarkable diversity of squirrel and chipmunk species (sciurids), and five named and several unnamed genospecies in the borrelia burgdorferi sensu lato group (bbsl) of bacteria as well, many of which utilize sciurids as reservoirs. we investigated the prevalence, spatial distribution, and diversity of bbsl in sciurids of california by literature search, pcr of 585 ear tissue samples from 15 sciurid species prospectively collected across 19 california counties, and dna sequencing ... | 2017 | 28976820 |
| pathologic findings in western gray squirrels (sciurus griseus) from a notoedric mange epidemic in the san bernardino mountains, california. | notoedric mange, caused by the contagious, burrowing mite notoedres centrifera, has been associated with several large-scale population declines of western gray squirrels (sciurus griseus) and has been a significant obstacle to population recovery in washington state where the species is listed as threatened. in 2009, residents and wildlife rehabilitators in the isolated san bernardino mountains of southern california reported a dramatic die-off of western gray squirrels, in what had been a prev ... | 2013 | 24533345 |
| notoedric mange in western gray squirrels from washington. | from february 1998 to july 1999, 65 western gray squirrels (sciurus griseus griseus) were trapped at three sites in klickitat county, washington (usa) as part of a home range and habitat use study. no squirrels (0/9) with mange lesions were identified in the initial trapping session (february and march 1998). during all subsequent trapping sessions (august 1998 through july 1999), squirrels with lesions consistent with notoedric mange, caused by the mite notoedres centrifera (douglasi), were cap ... | 2001 | 11504240 |
| orchopeas fleas (siphonaptera: ceratophyllidae) of the western gray squirrel, sciurus griseus. | | 1985 | 4078848 |
| visual acuity and spatial contrast sensitivity in tree squirrels. | the visual sensitivity of tree squirrels from three different species (two western gray squirrels, sciurus griseus; three fox squirrels, sciurus niger; and an eastern gray squirrel, sciurus carolinensis) was measured for spatial patterns defined by luminance differences. spatial contrast sensitivity functions were determined in behavioral discrimination experiments in which the stimuli were sinusoidally-modulated gratings. at an average luminance level of 3.4 cd/m(2) these squirrels were maximal ... | 1982 | 24923501 |
| naturally acquired toxoplasmosis in the gray squirrel, sciurus griseus, and its bearing on the laboratory diagnosis of rabies. | | 1959 | 13621032 |
| cross-sectional evaluation of multiple epidemiological cycles of leptospira species in peri-urban wildlife in california. | to perform a cross-sectional survey to estimate prevalence of and potential risk factors for leptospira spp infection and exposure in peri-urban wildlife throughout california. | 2020 | 33021456 |